Trap for rocket propellants



April 1l, 1950 c. N. HICKMAN TRAP Fon Roem murmurs Filed Nov. 16, 1944 I: LAR EN|:EN HH:KMAN,

fw A/ Patented Apr. Il, 1950 UNITED STATES PATENT oEFicE TRAP FOB ROCKET PROPELLANTS Clarence N. Hickman, Jackson Heights, N. Y. Application November 16, 1944, Serial No. 563,735 1 Claim. (Cl. 60-35.6)

(Granted under the act of March 3, 1883. as

amended April 30, 1928; 370 0. G. 757) The invention described herein may be manulectured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

of a rocket projectile comprising a hollow cylindrical housing I denning a rearwardly opening cylindrical chamber 2. -A nozzle member I is secured to rear end of housing I as by bolts 4.

This invention relates to rocket projectiles and 5 Nozzle member 3 is hollow and its hollow portion particularly to traps utilized to retain propellents is shaped to deilne a Venturi nozzle 5. In accordwithin the combustion chamber of the rocket ance with this invention, a trap I 0 ls provided projectile, comprising a cylindrical piece of tubing of such One of the well recognized diillculties encoundimension as to ilt snugly against the walls of tered in rocket projectiles utilizing powder as combustion chamber 2 and to be retained therein propellent, was the retention of the powder grains within the rocket motor combustion chamber until all of the powder was substantially consumed in combustion.

The following factors contributed to the diillculties encountered; first, a high inertia force is produced on the propellent due to the initial rapid acceleration of the rocket projectile. Such force naturally tends to discharge the propellent out of the rear of the projectile; secondly, the high velocity turbulent ilow of gases generated by the combustion of the propellent tends to carry the propellent out of the combustion chamber; thirdly, a trap which is eective in retaining small by nozzle member 3. The rear of trap I0 is slotted to produce a plurality of oppositely disposed tabs II which are bent inwardly to form the retaining portion of the trap. A propellent charge comprising a long cylindrical powder grain is mounted within the trap I0 and retained therein until substantially consumed by combustion by the bent over tabs I I oi the trap. The wall of trap I0 is preferably indented as shown at I2 at several places along the length of trap I0 so as to support the powder grain 20 within the center of trap. I 0. The powder grain 20 is ignited by any conventional form of igniter such as an electrical squib 2I mounted on a blowout disk 2 2 positioned pieces of the propellent within the motor chamadajacent the nozzle member 3. ber is generally found to oifer too much resistance A modied form of improved trap construction to the now of gases out of the chamber, hence is disclosed in Fig. 3. As shown in this ligure the permitting dangerous build-up of pressure within nozzle member 3 is screw fastened into the rear the chamber. end of housing I. A plurality of powder sticks 2l Accordingly it is an object of this invention to of relatively large diameter are loosely loaded into provide improved traps for the propellent of a combustion chamber 2, lying substantially parrocket projectile. allel to the axis of the chamber and are retained A particular object of this invention is to protherein by a trap member 30. Trap member 3l Vide an emcient trap for 8. IOcket motor wherein comprises a short tubular body portion 3| which such trap is of generally cylindrical shape and '35 fits snugly within combustion chamber 2 and has readily adaptable to quantity manufacture.. a plurality of transverse rods 32 suitably secured, The Specic nature of the invention as well as as by welding, across the forward end of tubular other objects and advantages thereof will clearly body 3|, The rods 32 in erregt form e grin which appeal' ferm a description of a preferred embediretains the powder sticks 20 within the combusment as shown in the accompanying drawing in 40 tion chamber 2 until they are substantially conwliich: sumed. The trap member 30 is in turn retained Fig. 1 represents a longitudinal sectional view within the combustion chamber 2 by the nozzle of a rocket motor embodying this invention showmember 3, ins a cylindrical trap member surrounding the It is apparent that the described trap constipropellent charge. tutes a simple, readily manufacturable structure Fis. 2 is a cross sectional View taken along the which positively retains the propellent charge plane 2 2 of Fig. 1. within the combustion chamber until the pro- Fig. 3 is a view similar to Fig. 1 of a modicapellent is substantially consumed and which nevtion ci this invention showing a cylindrical trap ertheless does not impair the now of the gases member located to the rear of the propellent developed within such chamber, charge. I claim:

Fis. 4 is a front elevational view of the trap A rocket motor comprising in combination, a member Shown in F15 3- tubular housing open at the rear and closed at Referring t0 Fig. 1 there iS ShOWIl in assembled its forward end, a hollow trap member in said relation the combustion chamber or rocket motor tubular housing, a propellent charge insertable lng inwardly projecting tabs at the rear end thereof constructed and med w um u The following references are of record in the propellant charge within said tubular housing me 0f this Went: until said llleisnize is eiobsttntially l s UNITED STATES PATENTS nozzlememprsecur eredi-po onosaid tubumr housing. the forward pm of :gig wii Nug, Umfme mnffmo extending partly across the open rear o I g' bnc x housing so as to retain said tmp member within zn'l'qss Lnb et l Aug' u n said tubulanhousinz and l. plurality of inwardly l0 FOREIGN PATENTS projecting' indentation: in said trap member u# Numb Country nmie ranged to engage and support slid propellant chnrge centrally within nid trop lnember. 1" Frm Ju 7' 1m CLARENCE N. HICKHAN. 

